1. Field of the Invention
The present invention relates to a hard film composition for capsules to be used for forming hard gelatin capsules and for band sealing such hard gelatin capsules.
2. Description of Related Art
Hard gelatin capsules are widely utilized in the field of pharmaceutical preparations due to ease of preparation and administration. However, conventional hard gelatin capsules have a problem in that the capsule film loses flexibility and suffers cracking or chipping if the capsules are packed with a hygroscopic agent, such as a powder or granular material, since the moisture contained in the capsule film is absorbed by the drug. Particularly, capsules are most commonly damaged when they are filled with such a drug and packaged or when they are taken out of the package for administration. Accordingly, limited types of drugs may be contained in conventional hard gelatin capsules in order to prevent embrittlement of the capsule films caused by moisture reduction.
Also known in the art are hard film compositions for hard gelatin capsules having flexibility which is increased by adding a plasticizer, such as glycerol, sorbitol, or polyethylene glycol to the gelatin. However, such hard gelatin capsules suffer problems in capsule manufacture in that the capsule films become too soft and the capsule drying speed is retarded due to the added plasticizer.
It is an object of the present invention to provide a hard film composition for capsules which will not be embrittled by a reduction in the moisture in the capsule film, even when a hygroscopic drug is contained in the capsule. Further, the present invention minimizes the cracking and chipping of the capsules and thus prevents leakage of the drug contained within the capsules.